Proposal Information

Specification Summary

Polarization: Dual linear with selection of circular using a 1/4 wave
plate for VLB observations

Number of beams: Two beams with dual polarization.

Beam separation: 4.7 arc-minutes in the Az direction.

Key Science

Based on the ASTRO-2010 Decadale Survey, four key research areas have
been identified for the GBT. The 4mm receiver would greatly enhance
the science capabilities in all of these areas.

Fundamental Physics -- With the VLBA, the GBT 4mm
receiver would allow us to probe the fundamental physics near the
base of powerful black hole jets in nearby galaxies.

The Context of Star Formation -- Molecular spectroscopy
of the deuterium species and the other important transitions
associated with dense molecular gas with the GBT 4mm receiver would
revolutionize studies of the structure and physical properties of
cold cloud cores from which stars form.

Origin of Life -- The GBT 4mm receiver will carry out
molecular spectroscopy of complex organic molecules and pre-biotic
molecules in the ISM and comets which are key for studying the
conditions from which life eventually forms.

Galaxies Across Cosmic Time -- The GBT 4mm receiver
would permit the studies of CO(1-0) at intermediate redshifts where
the evolution of galaxies is proceeding rapidly and allow for the
studies of the dense gas tracers, such as HCN and HCO+, in local
star-forming galaxies.